Joint calibration method and system for laser, inertia and image recognition

Abstract

The invention provides a laser, inertia and image recognition combined calibration method and system. Comprising the following steps: setting a parameter calibration checkerboard on a marble platform for detection, and leveling the parameter calibration checkerboard; carrying out inertial navigation IMU static parameter calibration and inertial navigation IMU dynamic parameter calibration on the inertial navigation IMU, and correcting an inertial navigation IMU error; irradiating laser spots of a laser into the parameter calibration checkerboard, shooting the parameter calibration checkerboard from different angles through a machine vision camera, and obtaining a parameter calibration checkerboard photo set; and joint calibration of parameters of a machine vision camera, an inertial navigation IMU and a laser is carried out, and automatic correction of external parameters of various precise positioning measuring instruments and high-precision measurement of local space are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-source sensor fusion precision measurement data processing positioning correction, and more specifically, to a laser, inertial and image recognition joint calibration method and system. Background Art

[0002] A current technological trend in the surveying and mapping and geographic information industries is to combine laser ranging, cameras, inertial navigation IMU sensors, and GNSS RTK to achieve three-dimensional spatial positioning of distant targets. The current industry does not have a batch alignment and precision correction method. The existing technical method corrects the installation angle of the laser and the equipment by reversing the distance error between the laser point B and the theoretical reference point B' at two places that are far apart, such as more than 10 meters, and achieves laser calibration through error and iteration. It has very high requirements for the environment and must be performed in an open outdoor environment. At the same time, it does not have batch and consistency. In addition, due to the existence of external parameters of rotation and translation between the laser emitter and the camera, if these parameters are inaccurate, the accuracy of image-assisted laser point search will be directly affected. Problems such as these remain to be solved. Therefore, it is necessary to propose a joint calibration method and system for laser, inertial and image recognition to at least partially solve the problems existing in the existing technology. Summary of the Invention

[0003] A series of simplified concepts are introduced in the summary of the invention, which will be further explained in detail in the specific implementation method. The summary of the invention does not mean to attempt to limit the key features and necessary technical features of the technical solution for protection, nor does it mean to attempt to determine the scope of protection of the technical solution for protection.

[0004] To at least partially solve the above problems, the present invention provides a joint calibration method of laser, inertial and image recognition, comprising:

[0005] S100, setting a parameter calibration checkerboard on a marble platform for testing, and leveling the parameter calibration checkerboard;

[0006] S200, performing IMU static parameter calibration and IMU dynamic parameter calibration on the IMU to correct IMU errors;

[0007] S300, irradiating a laser spot of a laser onto a parameter calibration checkerboard, photographing the parameter calibration checkerboard from different angles using a machine vision camera, and obtaining a set of photographs of the parameter calibration checkerboard;

[0008] S400 performs joint calibration of machine vision cameras, inertial navigation units (IMUs), and laser parameters, enabling automatic correction of external parameters of various precision positioning and measurement instruments and high-precision measurement of local spaces.

[0009] Preferably, S100 includes:

[0010] S101, setting a parameter calibration checkerboard on a marble platform for detection;

[0011] S102, using a marble platform for testing and a high-precision level, leveling the parameter calibration checkerboard to obtain a horizontal static parameter calibration checkerboard;

[0012] Setting a parameter calibration checkerboard on a marble platform for testing includes: spraying a first layer of checkerboard on the surface of the marble platform for testing through hollow shielding; spraying a second layer of checkerboard after the first layer of checkerboard is dry, and polishing the surface with high precision after the spraying is dry to form a parameter calibration checkerboard after high precision polishing.

[0013] Preferably, S200 includes:

[0014] S201, calibrating the static parameters of the inertial navigation IMU by a six-plane calibration method to correct the static error of the inertial navigation IMU;

[0015] S202, calibrating the gyroscope by the turntable, calibrating the dynamic parameters of the inertial navigation IMU, and correcting the dynamic error of the inertial navigation IMU;

[0016] The static parameter calibration of the inertial navigation IMU through the six-plane calibration method includes: placing the three axes of the inertial navigation IMU facing downward and upward for a set time, obtaining the six-plane measurement data of the three axes of the inertial navigation IMU; calibrating the static parameters of the inertial navigation IMU according to the error between the static acceleration and the gravity acceleration, and correcting the static error of the inertial navigation IMU.

[0017] Preferably, S300 includes:

[0018] S301, irradiating the laser spot of the laser onto the parameter calibration checkerboard;

[0019] S302, photographing the parameter calibration checkerboard from different angles using a machine vision camera; during the photographing process, the machine vision camera is stationary and photographs at least two of the parameter calibration checkerboard to obtain a set of parameter calibration checkerboard photographs;

[0020] S303 , during static shooting, records the pixel coordinate system of the laser spot in the image at the static moment, records the laser ranging distance, and records the inertial navigation IMU accelerometer output at the static moment.

[0021] Preferably, S400 includes:

[0022] S401: Establish parameter associations between the machine vision camera, inertial navigation unit (IMU), and laser, and perform joint calibration based on the parameter associations to achieve automatic calibration of external parameters for various precision positioning and measurement instruments.

[0023] S402, automatically calibrating the external parameters of various precision positioning measurement instruments to perform high-precision measurements in local space;

[0024] Establish parameter associations among machine vision cameras, inertial navigation IMUs, and lasers, and perform joint parameter calibration based on the parameter associations, including: obtaining the camera optical center position and camera posture in the parameter calibration checkerboard coordinate system at all shooting moments, and obtaining installation deviations; using homography transformation to obtain the physical coordinates of the laser spot in the parameter calibration checkerboard coordinate system; obtaining the first rotation matrix and translation vector between the camera and the laser spot; obtaining the second rotation matrix between the laser spot and the IMU coordinate system; and performing high-precision indication calibration of the laser spot image in laser measurement based on the calibration results of the second rotation matrix, translation vector, and the first rotation matrix, to perform high-precision measurement of local space.

[0025] The present invention provides a combined laser, inertial and image recognition calibration system, comprising:

[0026] A checkerboard leveling module for testing is used to set a parameter calibration checkerboard on a marble platform for testing, and level the parameter calibration checkerboard;

[0027] The inertial navigation IMU internal parameter calibration module performs IMU static parameter calibration and IMU dynamic parameter calibration on the inertial navigation IMU and corrects the IMU error;

[0028] The laser irradiation visual shooting module irradiates the laser spot of the laser on the parameter calibration checkerboard, and uses the machine vision camera to shoot the parameter calibration checkerboard from different angles to obtain a set of parameter calibration checkerboard photos;

[0029] The parameter joint calibration and correction measurement module performs joint calibration of machine vision cameras, inertial navigation IMUs, and laser parameters, enabling automatic correction of external parameters of various precision positioning measurement instruments and high-precision measurement of local spaces.

[0030] Preferably, the checkerboard leveling module for detection includes:

[0031] A detection platform chessboard setting unit is used to set parameter calibration chessboard grids on the marble platform used for detection;

[0032] The chessboard leveling unit uses a marble platform for testing and a high-precision level to level the parameter calibration chessboard and obtain the horizontal static parameter calibration chessboard;

[0033] Setting a parameter calibration checkerboard on a marble platform for testing includes: spraying a first layer of checkerboard on the surface of the marble platform for testing through hollow shielding; spraying a second layer of checkerboard after the first layer of checkerboard is dry, and polishing the surface with high precision after the spraying is dry to form a parameter calibration checkerboard after high precision polishing.

[0034] Preferably, the inertial navigation IMU internal parameter calibration module includes:

[0035] IMU static error calibration unit, which calibrates the static parameters of the inertial navigation IMU through the six-plane method and corrects the static error of the inertial navigation IMU;

[0036] The dynamic error calibration and correction unit calibrates the gyroscope through the turntable, calibrates the dynamic parameters of the inertial navigation IMU, and corrects the dynamic error of the inertial navigation IMU;

[0037] The static parameter calibration of the inertial navigation IMU through the six-plane calibration method includes: placing the three axes of the inertial navigation IMU facing downward and upward for a set time, obtaining the six-plane measurement data of the three axes of the inertial navigation IMU; calibrating the static parameters of the inertial navigation IMU according to the error between the static acceleration and the gravity acceleration, and correcting the static error of the inertial navigation IMU.

[0038] Preferably, the laser irradiation visual shooting module includes:

[0039] A laser irradiation unit irradiates a laser spot on the parameter calibration checkerboard;

[0040] The machine vision camera unit uses the machine vision camera to photograph the parameter calibration checkerboard from different angles; during the photographing process, the machine vision camera is stationary and photographs no less than two pictures of the parameter calibration checkerboard to obtain a set of picture of the parameter calibration checkerboard;

[0041] The laser parameter inertial navigation output unit records the pixel coordinate system of the laser spot in the image at the static moment, the laser ranging distance, and the inertial navigation IMU accelerometer output at the static moment during static shooting.

[0042] Preferably, the parameter joint calibration and correction measurement module includes:

[0043] The parameter association joint calibration unit establishes parameter associations between the machine vision camera, inertial navigation IMU, and laser, and performs parameter joint calibration based on the parameter associations, thus realizing automatic correction of external parameters of various precision positioning measurement instruments.

[0044] Automatic calibration measurement unit, which automatically calibrates based on external parameters of various precision positioning measurement instruments to perform high-precision measurements in local space;

[0045] Establish parameter associations among machine vision cameras, inertial navigation IMUs, and lasers, and perform joint parameter calibration based on the parameter associations, including: obtaining the camera optical center position and camera posture in the parameter calibration checkerboard coordinate system at all shooting moments, and obtaining installation deviations; using homography transformation to obtain the physical coordinates of the laser spot in the parameter calibration checkerboard coordinate system; obtaining the first rotation matrix and translation vector between the camera and the laser spot; obtaining the second rotation matrix between the laser spot and the IMU coordinate system; and performing high-precision indication calibration of the laser spot image in laser measurement based on the calibration results of the second rotation matrix, translation vector, and the first rotation matrix, to perform high-precision measurement of local space.

[0046] Compared with the prior art, the present invention has at least the following beneficial effects:

[0047] The present invention discloses a combined calibration method and system for laser, inertial and image recognition. The method comprises the following steps: setting a parameter calibration checkerboard on a marble platform for detection, leveling the parameter calibration checkerboard; performing static parameter calibration and dynamic parameter calibration on an inertial navigation unit (IMU) to correct IMU errors; irradiating a laser spot on the parameter calibration checkerboard, photographing the parameter calibration checkerboard from different angles using a machine vision camera, and obtaining a set of parameter calibration checkerboard photos; and performing combined calibration of the machine vision camera, the inertial navigation IMU and the laser to achieve automatic calibration of external parameters of various precision positioning measurement instruments and high-precision measurement of local space. The method can directly and quickly realize the automatic calibration of external parameters of various precision positioning measurement instruments and high-precision measurement of local space. It establishes the observation relationship between multiple sensors; it can efficiently complete the external parameter calibration between the camera and IMU; by identifying the position of the laser spot in the chessboard, it can efficiently complete the external parameter calibration of the camera and laser, and then complete the external parameter calibration between the laser, camera and IMU; it can be calibrated in indoor environments and does not rely on GNSS positioning; it greatly improves the accuracy, consistency and efficiency of calibration; it solves the technical problem of laser spots being difficult to distinguish or invisible under strong light through the camera, significantly improving the utilization efficiency; it realizes the alignment of the laser and the inertial navigation, and performs the external parameter alignment between the laser emitter and the camera, which significantly improves the calibration efficiency.

[0048] The present invention describes a combined laser, inertial, and image recognition calibration method and system. Other advantages, objectives, and features of the present invention will be partially reflected in the following description and partially understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0050] Figure 1This is a diagram of an embodiment of a combined laser, inertial and image recognition calibration system according to the present invention.

[0051] Figure 2 This is a diagram of an embodiment of the combined calibration method of laser, inertial and image recognition described in the present invention.

[0052] Figure 3 This is a diagram illustrating an application example of a combined laser, inertial, and image recognition calibration method and system according to the present invention. DETAILED DESCRIPTION

[0053] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments so that those skilled in the art can implement the invention with reference to the description. As shown in the drawings, the present invention provides a combined calibration method of laser, inertial, and image recognition, including:

[0054] S100, setting a parameter calibration checkerboard on a marble platform for testing, and leveling the parameter calibration checkerboard;

[0055] S200, performing IMU static parameter calibration and IMU dynamic parameter calibration on the IMU to correct IMU errors;

[0056] S300, irradiating a laser spot of a laser onto a parameter calibration checkerboard, photographing the parameter calibration checkerboard from different angles using a machine vision camera, and obtaining a set of photographs of the parameter calibration checkerboard;

[0057] S400 performs joint calibration of machine vision cameras, inertial navigation units (IMUs), and laser parameters, enabling automatic correction of external parameters of various precision positioning and measurement instruments and high-precision measurement of local spaces.

[0058] The principle and effect of the above technical solution are as follows: The present invention provides a joint calibration method of laser, inertia and image recognition, including: setting a parameter calibration checkerboard on a marble platform for detection and leveling the parameter calibration checkerboard; performing static parameter calibration and dynamic parameter calibration on the inertial navigation IMU and correcting the inertial navigation IMU error; irradiating the laser spot of the laser into the parameter calibration checkerboard, photographing the parameter calibration checkerboard from different angles through a machine vision camera, and obtaining a set of photos of the parameter calibration checkerboard; irradiating the laser spot of the laser into the parameter calibration checkerboard, photographing the parameter calibration checkerboard from different angles through a machine vision camera, and obtaining a set of photos of the parameter calibration checkerboard. , obtaining a set of parameter calibration checkerboard photos includes: irradiating the laser spot of the laser into the parameter calibration checkerboard, and setting a scattering light-absorbing layer on the surface of the parameter calibration checkerboard to prevent the strong light of the laser spot from causing halo and focus misalignment in the camera photo. The scattering light-absorbing layer includes a frosted scattering surface and an underlying light-absorbing film. When the laser spot irradiates the scattering light-absorbing layer, the frosted scattering surface scatters part of the strong light of the laser spot, and the other part of the laser line passing through the frosted scattering surface is absorbed by the underlying light-absorbing film, thereby further weakening the strong light of the laser spot; using a machine vision camera to shoot the parameter calibration checkerboard from different angles to obtain multiple parameter calibration checkerboard photos, and multiple parameter calibration checkerboard photos are taken. A set of calibration chessboard photos is formed to obtain a set of parameter calibration chessboard photos; the problem of strong light reflected from laser spots interfering with machine vision camera photography is solved, and the problem of camera photography halo and focus misalignment is solved; the shooting accuracy of machine vision cameras is significantly improved; multiple parameter calibration chessboard photos are verified to further reduce errors; the parameters of machine vision cameras, inertial navigation IMUs and lasers are jointly calibrated to achieve automatic correction of external parameters of various precision positioning measurement instruments and high-precision measurement of local space; the observation relationship between multiple sensors is directly and quickly established; the external parameter calibration between cameras and IMUs can be completed efficiently; by identifying the position of laser spots on the chessboard , can efficiently complete the external parameter calibration of the camera and laser, and then complete the external parameter calibration between the laser, camera and IMU; it can be calibrated in indoor environments and does not rely on GNSS positioning; it greatly improves the accuracy, consistency and efficiency of calibration; by introducing a camera to observe the laser point of the laser in the chessboard coordinates, the external parameter calibration of the laser, IMU and camera is completed efficiently and accurately through machine vision automation; the camera solves the technical problem that the laser point is difficult to distinguish or invisible under strong light, significantly improving the utilization efficiency; the laser and inertial navigation are aligned, and the external parameter alignment between the laser emitter and the camera is performed, which significantly improves the calibration efficiency.

[0059] In one embodiment, S100 includes:

[0060] S101, setting a parameter calibration checkerboard on a marble platform for detection;

[0061] S102, using a marble platform for testing and a high-precision level, leveling the parameter calibration checkerboard to obtain a horizontal static parameter calibration checkerboard;

[0062] Setting a parameter calibration checkerboard on a marble platform for testing includes: spraying a first layer of checkerboard on the surface of the marble platform for testing through hollow shielding; spraying a second layer of checkerboard after the first layer of checkerboard is dry, and polishing the surface with high precision after the spraying is dry to form a parameter calibration checkerboard after high precision polishing.

[0063] The principle and effect of the above technical solution are as follows: setting a parameter calibration checkerboard on the marble platform for testing; using the marble platform for testing and a high-precision level to level the parameter calibration checkerboard to obtain a horizontal static parameter calibration checkerboard; setting a parameter calibration checkerboard on the marble platform for testing includes: spraying a first layer of checkerboard on the surface of the marble platform for testing through hollow shielding; spraying a second layer of checkerboard after the first layer of checkerboard is dried, and performing high-precision polishing and leveling on the surface after the spraying is dry to form a parameter calibration checkerboard after high-precision polishing; the marble platform for testing includes: a hydraulic anti-vibration base 11, a high-precision marble platform 12, a platform stable fulcrum group 13, and a displacement pressure detection device 14; the hydraulic anti-vibration base is a grooved stone base that accommodates the high-precision marble platform; the platform stable fulcrum group is provided with multiple groups of anti-vibration constant-volume hydraulic rods 131 and a hydraulic controller 132; the anti-vibration constant-volume hydraulic rods disperse single-point vibration and buffer multi-point vibration through hydraulic oil; multiple groups of anti-vibration The constant-volume hydraulic rod supports multiple platform stabilization fulcrums 133; the platform stabilization fulcrums support the bottom and surrounding areas of the high-precision marble platform; the displacement pressure detection device includes multiple groups of pressure detection sensors 141 and a data operation processor 142; the multiple groups of pressure detection sensors are arranged at the bottom and surrounding areas of the high-precision marble platform to detect the multi-point vertical pressure and multi-point horizontal pressure between the high-precision marble platform and the hydraulic anti-vibration base; the data operation processor analyzes the pressure distribution state of the high-precision marble platform based on the multi-point vertical pressure and the multi-point horizontal pressure, and predicts the displacement trend of the high-precision marble platform in all directions; analyzes the pressure distribution state of the high-precision marble platform, and when the static pressure difference between the vertical pressure of any point of the multi-point vertical pressure and the static vertical pressure of this point after leveling exceeds the set static pressure difference, it is predicted that there is a displacement trend in the direction of this point; the hydraulic controller is used to control the increase or decrease of the support force of the anti-vibration constant-volume hydraulic rod to offset the static pressure difference and the displacement trend in the direction of this point.

[0064] In one embodiment, S200 includes:

[0065] S201, calibrating the static parameters of the inertial navigation IMU by a six-plane calibration method to correct the static error of the inertial navigation IMU;

[0066] S202, calibrating the gyroscope by the turntable, calibrating the dynamic parameters of the inertial navigation IMU, and correcting the dynamic error of the inertial navigation IMU;

[0067] The static parameter calibration of the inertial navigation IMU through the six-plane calibration method includes: placing the three axes of the inertial navigation IMU facing downward and upward for a set time, obtaining the six-plane measurement data of the three axes of the inertial navigation IMU; calibrating the static parameters of the inertial navigation IMU according to the error between the static acceleration and the gravity acceleration, and correcting the static error of the inertial navigation IMU.

[0068] The principle and effect of the above technical solution are as follows: the static parameters of the inertial navigation IMU are calibrated by the six-plane method to correct the static error of the inertial navigation IMU; the gyroscope is calibrated by the turntable to calibrate the dynamic parameters of the inertial navigation IMU to correct the dynamic error of the inertial navigation IMU;

[0069] The static parameter calibration of the inertial navigation IMU by the six-plane calibration method includes: placing the three axes of the inertial navigation IMU downward and upward for a set time, and obtaining the six-plane measurement data of the three axes of the inertial navigation IMU; calibrating the static parameters of the inertial navigation IMU according to the error of static acceleration and gravity acceleration, and correcting the static error of the inertial navigation IMU; calibrating the gyroscope by the turntable, and calibrating the dynamic parameters of the inertial navigation IMU. Correcting the dynamic error of the inertial navigation IMU includes: fixing the inertial navigation IMU on the turntable calibration frame of the turntable calibration gyroscope, correcting the early speed error and transmission error through the differential pulley micro-motion mechanism, and starting measurement, automatically rolling the turntable calibration frame to drive the inertial navigation IMU to flip; constructing the integral speed six-plane method The model is designed to obtain the inertial navigation unit (IMU) flip angle through integration according to the inertial navigation unit (IMU) rotation time dt, and set the inertial navigation unit (IMU) attitude position. When the turntable inner frame and the turntable outer frame are at the set calibration angle, the inertial navigation unit (IMU) attitude position is reached. The inertial navigation unit (IMU) rotation angular velocity is obtained according to the inertial navigation unit (IMU) rotation time dt and the inertial navigation unit (IMU) flip angle. The inertial navigation unit (IMU) dynamic acceleration is compared with the turntable calibration gyroscope acceleration, and the acceleration error is corrected to correct the inertial navigation unit (IMU) dynamic error. The differential pulley micro-motion mechanism rotates the motor speed in a unidirectional manner through a multi-step differential pulley and a transmission belt, and starts measurement after the motor speed has reached the set number of turns to correct the initial speed error and transmission error. This significantly reduces the inertial error and improves the correction accuracy.

[0070] In one embodiment, S300 includes:

[0071] S301, irradiating the laser spot of the laser onto the parameter calibration checkerboard;

[0072] S302, photographing the parameter calibration checkerboard from different angles using a machine vision camera; during the photographing process, the machine vision camera is stationary and photographs at least two of the parameter calibration checkerboard to obtain a set of parameter calibration checkerboard photographs;

[0073] S303 , during static shooting, records the pixel coordinate system of the laser spot in the image at the static moment, records the laser ranging distance, and records the inertial navigation IMU accelerometer output at the static moment.

[0074] The principle and effect of the above technical solution are as follows: irradiate the laser spot of the laser into the parameter calibration checkerboard; use the machine vision camera to shoot the parameter calibration checkerboard from different angles; during the shooting process, the machine vision camera takes no less than two pictures of the parameter calibration checkerboard to obtain a set of pictures of the parameter calibration checkerboard; when shooting at rest, record the pixel coordinates of the laser spot in the image at the static moment, record the laser ranging distance, and record the inertial navigation IMU accelerometer output at the static moment; the pixel coordinates of the laser spot in the image at the static moment are expressed as p s , laser ranging distance is expressed as D s , the IMU accelerometer output at the static moment is expressed as f s .

[0075] In one embodiment, S400 includes:

[0076] S401: Establish parameter associations between the machine vision camera, inertial navigation unit (IMU), and laser, and perform joint calibration based on the parameter associations to achieve automatic calibration of external parameters for various precision positioning and measurement instruments.

[0077] S402, automatically calibrating the external parameters of various precision positioning measurement instruments to perform high-precision measurements in local space;

[0078] Establish parameter associations among machine vision cameras, inertial navigation IMUs, and lasers, and perform joint parameter calibration based on the parameter associations, including: obtaining the camera optical center position and camera posture in the parameter calibration checkerboard coordinate system at all shooting moments, and obtaining installation deviations; using homography transformation to obtain the physical coordinates of the laser spot in the parameter calibration checkerboard coordinate system; obtaining the first rotation matrix and translation vector between the camera and the laser spot; obtaining the second rotation matrix between the laser spot and the IMU coordinate system; and performing high-precision indication calibration of the laser spot image in laser measurement based on the calibration results of the second rotation matrix, translation vector, and the first rotation matrix, to perform high-precision measurement of local space.

[0079] The principle and effect of the above technical solution are: establishing parameter associations among machine vision cameras, inertial navigation IMUs and lasers, and performing joint parameter calibration based on the parameter associations to realize automatic correction of external parameters of various precision positioning measuring instruments; performing high-precision measurement of local space based on automatic correction of external parameters of various precision positioning measuring instruments; establishing parameter associations among machine vision cameras, inertial navigation IMUs and lasers, and performing joint parameter calibration based on the parameter associations, including: obtaining the camera optical center position and camera posture in the parameter calibration checkerboard coordinate system of the camera at all shooting moments, and obtaining the installation deviation; obtaining the physical coordinates of the laser spot in the parameter calibration checkerboard coordinate system by using homography transformation; obtaining the first rotation matrix and translation vector between the camera and the laser spot; obtaining the second rotation matrix between the laser spot and the IMU coordinate system; performing high-precision indication calibration of the laser spot image calibration in laser measurement based on the calibration results of the second rotation matrix, translation vector and the first rotation matrix, and performing high-precision measurement of local space;

[0080] The camera intrinsic parameter calibration is performed using the parameter calibration checkerboard photo set. During the process of obtaining the camera intrinsic parameter calibration, the camera optical center positions P1 to P1 in the parameter calibration checkerboard coordinate system at all shooting moments are obtained according to the shooting time of each parameter calibration checkerboard photo. n and camera pose to The horizontal static parameter calibration checkerboard has been leveled, the camera posture to Equivalent to the camera pose in the geodetic coordinate system to Get P1 to P n The camera position P at the static moment s , get to Camera pose captured at a still moment The pixel coordinates of the laser spot at the static moment in the image are represented as p s , laser ranging distance is expressed as D s , the IMU accelerometer output at the static moment is expressed as f s ;

[0081] The theoretical value of the relative angle between the machine vision camera and the IMU is The installation deviation caused by the installation process is The local gravity vector is g; the installation deviation is obtained using the least squares method The parameter calibration checkerboard corner points in the static shooting parameter calibration checkerboard photo set are dedistorted to obtain the dedistorted parameter calibration checkerboard pixel coordinates; the parameter calibration checkerboard corner points are used to calibrate the checkerboard pixel coordinates and the parameter calibration checkerboard physical coordinates to obtain the homography matrix h; the physical coordinates p of the laser spot in the parameter calibration checkerboard coordinate system are obtained using the homography transformation r ;p r Set to the transposed matrix of matrix [prxpry 1]; p s Set to the transposed matrix of matrix [psx psy 1]; set Ds to the distance between the camera and the laser; use the least squares method to obtain the first rotation matrix between the camera and the laser And the translation vector L; obtain the second rotation matrix between the laser spot and the IMU coordinate system Set the pixel coordinates of the laser point in the image; obtain the rotation matrix from the IMU coordinate system to the geographic coordinate system through the inertial navigation IMU, and obtain the laser measurement point P according to the coordinates of the GNSS antenna phase center in the camera coordinate system. t Accurate coordinates in the geographic coordinate system; according to the second rotation matrix Translation vector L and first rotation matrix Calibration results, perform high-precision indication calibration of laser spot image calibration in laser measurement; perform high-precision measurement of local space; complete high-precision indication calibration and measurement tasks of laser spot image calibration in laser measurement.

[0082] The present invention provides a combined laser, inertial and image recognition calibration system, comprising:

[0083] A checkerboard leveling module for testing is used to set a parameter calibration checkerboard on a marble platform for testing, and level the parameter calibration checkerboard;

[0084] The inertial navigation IMU internal parameter calibration module performs IMU static parameter calibration and IMU dynamic parameter calibration on the inertial navigation IMU and corrects the IMU error;

[0085] The laser irradiation visual shooting module irradiates the laser spot of the laser on the parameter calibration checkerboard, and uses the machine vision camera to shoot the parameter calibration checkerboard from different angles to obtain a set of parameter calibration checkerboard photos;

[0086] The parameter joint calibration and correction measurement module performs joint calibration of machine vision cameras, inertial navigation IMUs, and laser parameters, enabling automatic correction of external parameters of various precision positioning measurement instruments and high-precision measurement of local spaces.

[0087] The principle and effect of the above technical solution are as follows: the present invention provides a joint calibration system of laser, inertia and image recognition, including: a detection chessboard leveling module, which sets a parameter calibration chessboard on a detection marble platform and levels the parameter calibration chessboard; an inertial navigation IMU internal parameter calibration module, which performs inertial navigation IMU static parameter calibration and inertial navigation IMU dynamic parameter calibration on the inertial navigation IMU and corrects the inertial navigation IMU error; a laser irradiation visual shooting module, which irradiates the laser spot of the laser into the parameter calibration chessboard, shoots the parameter calibration chessboard from different angles through a machine vision camera, and obtains a set of parameter calibration chessboard photos; the laser spot of the laser is irradiated on the parameter calibration chessboard, and the laser spot is irradiated on the parameter calibration chessboard. The spot is irradiated on the parameter calibration checkerboard, and the parameter calibration checkerboard is photographed from different angles by a machine vision camera to obtain a set of parameter calibration checkerboard photos, including: irradiating the laser spot of the laser on the parameter calibration checkerboard, and setting a scattering light-absorbing layer on the surface of the parameter calibration checkerboard to prevent the strong light of the laser spot from causing halo and focus misalignment in camera photography. The scattering light-absorbing layer includes a frosted scattering surface and an underlying light-absorbing film. When the laser spot irradiates the scattering light-absorbing layer, the frosted scattering surface scatters part of the strong light of the laser spot, and the other part of the laser line passing through the frosted scattering surface is absorbed by the underlying light-absorbing film, thereby further weakening the strong light of the laser spot; The machine vision camera shoots the parameter calibration checkerboard from different angles to obtain multiple parameter calibration checkerboard photos, and the multiple parameter calibration checkerboard photos are grouped together to obtain a parameter calibration checkerboard photo set; solve the problem of strong light reflection from laser spots interfering with the machine vision camera photography, and solve the camera photography halo and focus misalignment problems; significantly improve the shooting accuracy of the machine vision camera; multiple parameter calibration checkerboard photos are verified to further reduce errors; the parameter joint calibration correction measurement module performs parameter joint calibration of the machine vision camera, inertial navigation IMU and laser, and realizes automatic calibration of external parameters of various precision positioning measurement instruments and high-precision measurement of local space; direct and fast An observation relationship between multiple sensors is established; the extrinsic parameter calibration between the camera and IMU can be completed efficiently; by identifying the position of the laser spot on the chessboard, the extrinsic parameter calibration of the camera and laser can be completed efficiently, and then the extrinsic parameter calibration between the laser, camera and IMU can be completed; indoor environment can be calibrated without relying on GNSS positioning; the accuracy, consistency and efficiency of calibration are greatly improved; the technical problem of laser spots being difficult to distinguish or invisible under strong light is solved through the camera, significantly improving the utilization efficiency; the laser and inertial navigation are aligned, and the extrinsic parameter alignment between the laser emitter and the camera is performed, which significantly improves the calibration efficiency.

[0088] In one embodiment, a checkerboard leveling module for detection includes:

[0089] A detection platform chessboard setting unit is used to set parameter calibration chessboard grids on the marble platform used for detection;

[0090] The chessboard leveling unit uses a marble platform for testing and a high-precision level to level the parameter calibration chessboard and obtain the horizontal static parameter calibration chessboard;

[0091] Setting a parameter calibration checkerboard on a marble platform for testing includes: spraying a first layer of checkerboard on the surface of the marble platform for testing through hollow shielding; spraying a second layer of checkerboard after the first layer of checkerboard is dry, and polishing the surface with high precision after the spraying is dry to form a parameter calibration checkerboard after high precision polishing.

[0092] The principle and effect of the above technical solution are as follows: the detection chessboard leveling module includes: a detection platform chessboard setting unit, which sets a parameter calibration chessboard on the detection marble platform; a chessboard leveling unit, which uses the detection marble platform and a high-precision spirit level to level the parameter calibration chessboard and obtain a horizontal static parameter calibration chessboard; setting the parameter calibration chessboard on the detection marble platform includes: spraying a first layer of chessboard on the surface of the detection marble platform through hollow shielding; spraying a second layer of chessboard after the first layer of chessboard is dried, and performing high-precision polishing and leveling on the surface after the spraying is dry to form a high-precision polished and leveled parameter calibration chessboard; the detection marble platform includes: a hydraulic anti-vibration base 11, a high-precision marble platform 12, a platform stable fulcrum group 13, and a displacement pressure detection device 14; the hydraulic anti-vibration base is a grooved stone base that accommodates the high-precision marble platform; the platform stable fulcrum group is provided with a plurality of groups of anti-vibration constant-volume hydraulic rods 131 and a hydraulic controller 132; the anti-vibration constant-volume hydraulic rods disperse the hydraulic oil Single-point vibration and buffering of multi-point vibration; multiple groups of anti-vibration constant-volume hydraulic rods correspondingly support multiple platform stabilization fulcrums 133; the platform stabilization fulcrums support the bottom and surrounding areas of the high-precision marble platform; the displacement pressure detection device includes multiple groups of pressure detection sensors 141 and a data operation processor 142; multiple groups of pressure detection sensors are arranged at the bottom and surrounding areas of the high-precision marble platform to detect multi-point vertical pressure and multi-point horizontal pressure between the high-precision marble platform and the hydraulic anti-vibration base; the data operation processor analyzes the pressure distribution state of the high-precision marble platform according to the multi-point vertical pressure and multi-point horizontal pressure, and predicts the displacement trend of the high-precision marble platform in all directions; analyzes the pressure distribution state of the high-precision marble platform, and when the static pressure difference between the vertical pressure of any point of the multi-point vertical pressure and the static vertical pressure of this point after leveling exceeds the set static pressure difference, it is predicted that there is a displacement trend in the direction of this point; the hydraulic controller is used to control the increase or decrease of the support force of the anti-vibration constant-volume hydraulic rod to offset the static pressure difference and the displacement trend in the direction of this point.

[0093] In one embodiment, the inertial navigation IMU internal parameter calibration module includes:

[0094] IMU static error calibration unit, which calibrates the static parameters of the inertial navigation IMU through the six-plane method and corrects the static error of the inertial navigation IMU;

[0095] The dynamic error calibration and correction unit calibrates the gyroscope through the turntable, calibrates the dynamic parameters of the inertial navigation IMU, and corrects the dynamic error of the inertial navigation IMU;

[0096] The static parameter calibration of the inertial navigation IMU through the six-plane calibration method includes: placing the three axes of the inertial navigation IMU facing downward and upward for a set time, obtaining the six-plane measurement data of the three axes of the inertial navigation IMU; calibrating the static parameters of the inertial navigation IMU according to the error between the static acceleration and the gravity acceleration, and correcting the static error of the inertial navigation IMU.

[0097] The principle and effect of the above technical solution are as follows: the inertial navigation IMU internal parameter calibration module includes: an IMU static error calibration unit, which calibrates the static parameters of the inertial navigation IMU through the six-plane method and corrects the static error of the inertial navigation IMU; a dynamic error calibration correction unit, which calibrates the gyroscope through the turntable, calibrates the dynamic parameters of the inertial navigation IMU, and corrects the dynamic error of the inertial navigation IMU; calibrating the static parameters of the inertial navigation IMU through the six-plane method includes: placing the three axes of the inertial navigation IMU downward and upward for a set time, and obtaining the six-plane measurement data of the three axes of the inertial navigation IMU; calibrating the static parameters of the inertial navigation IMU according to the error between static acceleration and gravity acceleration, and correcting the static error of the inertial navigation IMU; calibrating the gyroscope through the turntable, calibrating the dynamic parameters of the inertial navigation IMU, and correcting the dynamic error of the inertial navigation IMU includes: fixing the inertial navigation IMU on the turntable to calibrate the gyroscope On the turntable calibration frame, measurement begins after correcting the initial speed error and transmission error through the differential pulley micro-motion mechanism, and automatically rolls the turntable calibration frame to drive the inertial navigation IMU to flip; a six-face method model of integral speed is constructed, and the inertial navigation IMU flip angle is obtained by integration according to the inertial navigation IMU rotation time dt, and the inertial navigation IMU attitude position is set; when the turntable inner frame and the turntable outer frame are at the set calibration angle, the inertial navigation IMU attitude position is reached; based on the inertial navigation IMU rotation time dt and the inertial navigation IMU flip angle, the inertial navigation IMU rotation angular velocity is obtained; the inertial navigation IMU dynamic acceleration is compared with the turntable calibration gyroscope acceleration, and the acceleration error is corrected to correct the inertial navigation IMU dynamic error; the differential pulley micro-motion mechanism rotates the motor speed through a one-way differential rotation through multiple-step diameter differential pulleys and transmission belts, and measurement begins after the set number of circles are corrected for the initial speed error and transmission error; significantly reduces inertia error and improves calibration accuracy.

[0098] In one embodiment, the laser irradiation visual capture module includes:

[0099] A laser irradiation unit irradiates a laser spot on the parameter calibration checkerboard;

[0100] The machine vision camera unit uses the machine vision camera to photograph the parameter calibration checkerboard from different angles; during the photographing process, the machine vision camera is stationary and photographs no less than two pictures of the parameter calibration checkerboard to obtain a set of picture of the parameter calibration checkerboard;

[0101] The laser parameter inertial navigation output unit records the pixel coordinate system of the laser spot in the image at the static moment, the laser ranging distance, and the inertial navigation IMU accelerometer output at the static moment during static shooting.

[0102] The principle and effect of the above technical solution are: a laser irradiation visual shooting module, including: a laser irradiation unit, which irradiates the laser spot of the laser into the parameter calibration checkerboard; a machine vision camera unit, which shoots the parameter calibration checkerboard from different angles through the machine vision camera; during the shooting process, the machine vision camera statically shoots no less than two parameter calibration checkerboard photos to obtain a parameter calibration checkerboard photo set; a laser parameter inertial navigation output unit, which, during static shooting, records the pixel coordinate system of the laser spot in the image at the static moment, records the laser ranging distance, and records the inertial navigation IMU accelerometer output at the static moment.

[0103] In one embodiment, the parameter joint calibration and correction measurement module includes:

[0104] The parameter association joint calibration unit establishes parameter associations between the machine vision camera, inertial navigation IMU, and laser, and performs parameter joint calibration based on the parameter associations, thus realizing automatic correction of external parameters of various precision positioning measurement instruments.

[0105] Automatic calibration measurement unit, which automatically calibrates based on external parameters of various precision positioning measurement instruments to perform high-precision measurements in local space;

[0106] Establish parameter associations among machine vision cameras, inertial navigation IMUs, and lasers, and perform joint parameter calibration based on the parameter associations, including: obtaining the camera optical center position and camera posture in the parameter calibration checkerboard coordinate system at all shooting moments, and obtaining installation deviations; using homography transformation to obtain the physical coordinates of the laser spot in the parameter calibration checkerboard coordinate system; obtaining the first rotation matrix and translation vector between the camera and the laser spot; obtaining the second rotation matrix between the laser spot and the IMU coordinate system; and performing high-precision indication calibration of the laser spot image in laser measurement based on the calibration results of the second rotation matrix, translation vector, and the first rotation matrix, to perform high-precision measurement of local space.

[0107] The principle and effect of the above technical solution are as follows: parameter joint calibration correction measurement module, including: parameter association joint calibration unit, establishing parameter association of machine vision camera, inertial navigation IMU and laser, performing parameter joint calibration according to parameter association, realizing automatic correction of external parameters of various precision positioning measurement instruments; automatic correction measurement unit, performing high-precision measurement of local space according to external parameters of various precision positioning measurement instruments; establishing parameter association of machine vision camera, inertial navigation IMU and laser, performing parameter joint calibration according to parameter association, including: obtaining the relative position of the camera optical center in the parameter calibration checkerboard coordinate system at all shooting moments The optical center position of the machine and the camera posture are used to obtain the installation deviation; the physical coordinates of the laser spot in the parameter calibration checkerboard coordinate system are obtained by using homography transformation; the first rotation matrix and translation vector between the camera and the laser spot are obtained; obtaining the first rotation matrix and translation vector between the camera and the laser spot includes: obtaining the first rotation matrix and translation vector between the camera position and the laser; obtaining the second rotation matrix between the laser spot and the IMU coordinate system; according to the calibration results of the second rotation matrix, translation vector and the first rotation matrix, the laser spot image calibration in the laser measurement is carried out for high-precision indication calibration, and high-precision measurement of the local space is carried out;

[0108] The camera intrinsic parameter calibration is performed using the parameter calibration checkerboard photo set. During the process of obtaining the camera intrinsic parameter calibration, the camera optical center positions P1 to P1 in the parameter calibration checkerboard coordinate system at all shooting moments are obtained according to the shooting time of each parameter calibration checkerboard photo. n and camera pose to The horizontal static parameter calibration checkerboard has been leveled, the camera posture to Equivalent to the camera pose in the geodetic coordinate system to Get P1 to P n The camera position P at the static moment s , get to Camera pose captured at a still moment The pixel coordinates of the laser spot at the static moment in the image are represented as p s , laser ranging distance is expressed as D s , the IMU accelerometer output at the static moment is expressed as f s ;

[0109] The theoretical value of the relative angle between the machine vision camera and the IMU is The installation deviation caused by the installation process is The local gravity vector is g; the installation deviation is obtained using the least squares method The parameter calibration checkerboard corner points in the static shooting parameter calibration checkerboard photo set are dedistorted to obtain the dedistorted parameter calibration checkerboard pixel coordinates; the parameter calibration checkerboard corner points are used to calibrate the checkerboard pixel coordinates and the parameter calibration checkerboard physical coordinates to obtain the homography matrix h; the physical coordinates p of the laser spot in the parameter calibration checkerboard coordinate system are obtained using the homography transformation r ;p r Set to the transposed matrix of matrix [prx pry1]; p s Set to the transposed matrix of matrix [psx psy 1]; use the least squares method to obtain the first rotation matrix between the camera and the laser and translation vector L; Ds is the distance between the camera and the laser; obtain the second rotation matrix between the laser spot and the IMU coordinate system; set the pixel coordinates of the laser point in the image; obtain the rotation matrix from the IMU coordinate system to the geographic coordinate system through the inertial navigation IMU, and obtain the laser measurement point P according to the coordinates of the GNSS antenna phase center in the camera coordinate system t Accurate coordinates in the geographic coordinate system; according to the second rotation matrix Translation vector L and first rotation matrix Calibration results, perform high-precision indication calibration of laser spot image calibration in laser measurement; perform high-precision measurement of local space; complete high-precision indication calibration and measurement tasks of laser spot image calibration in laser measurement.

[0110] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A joint calibration method of laser, inertial and image recognition, characterized in that: include: S100, setting a parameter calibration checkerboard on a marble platform for testing, and leveling the parameter calibration checkerboard; S200, performing IMU static parameter calibration and IMU dynamic parameter calibration on the IMU to correct IMU errors; S300, irradiating a laser spot of a laser onto a parameter calibration checkerboard, photographing the parameter calibration checkerboard from different angles using a machine vision camera, and obtaining a set of photographs of the parameter calibration checkerboard; S400 performs joint calibration of machine vision cameras, inertial navigation units (IMUs), and laser parameters, enabling automatic correction of external parameters of various precision positioning and measurement instruments and high-precision measurement of local spaces.

2. The combined calibration method of laser, inertial and image recognition according to claim 1, characterized in that: S100 includes: S101, setting a parameter calibration checkerboard on a marble platform for detection; S102, using a marble platform for testing and a high-precision level, leveling the parameter calibration checkerboard to obtain a horizontal static parameter calibration checkerboard; Setting a parameter calibration checkerboard on a marble platform for testing includes: spraying a first layer of checkerboard on the surface of the marble platform for testing through hollow shielding; spraying a second layer of checkerboard after the first layer of checkerboard is dry, and polishing the surface with high precision after the spraying is dry to form a parameter calibration checkerboard after high precision polishing.

3. The combined calibration method of laser, inertial and image recognition according to claim 1, characterized in that: S200 includes: S201, calibrating the static parameters of the inertial navigation IMU by a six-plane calibration method to correct the static error of the inertial navigation IMU; S202, calibrating the gyroscope by the turntable, calibrating the dynamic parameters of the inertial navigation IMU, and correcting the dynamic error of the inertial navigation IMU; The static parameter calibration of the inertial navigation IMU through the six-plane calibration method includes: placing the three axes of the inertial navigation IMU facing downward and upward for a set time, obtaining the six-plane measurement data of the three axes of the inertial navigation IMU; calibrating the static parameters of the inertial navigation IMU according to the error between the static acceleration and the gravity acceleration, and correcting the static error of the inertial navigation IMU.

4. The laser, inertial and image recognition joint calibration method according to claim 1, characterized in that: S300 includes: S301, irradiating the laser spot of the laser onto the parameter calibration checkerboard; S302, photographing the parameter calibration checkerboard from different angles using a machine vision camera; during the photographing process, the machine vision camera is stationary and photographs at least two of the parameter calibration checkerboard to obtain a set of parameter calibration checkerboard photographs; S303 , during static shooting, records the pixel coordinate system of the laser spot in the image at the static moment, records the laser ranging distance, and records the inertial navigation IMU accelerometer output at the static moment.

5. The combined calibration method of laser, inertial and image recognition according to claim 1, characterized in that: S400 includes: S401: Establish parameter associations between the machine vision camera, inertial navigation unit (IMU), and laser, and perform joint calibration based on the parameter associations to achieve automatic calibration of external parameters for various precision positioning and measurement instruments. S402, automatically calibrating the external parameters of various precision positioning measurement instruments to perform high-precision measurements in local space; Establish parameter associations among machine vision cameras, inertial navigation IMUs, and lasers, and perform joint parameter calibration based on the parameter associations, including: obtaining the camera optical center position and camera posture in the parameter calibration checkerboard coordinate system at all shooting moments, and obtaining installation deviations; using homography transformation to obtain the physical coordinates of the laser spot in the parameter calibration checkerboard coordinate system; obtaining the first rotation matrix and translation vector between the camera and the laser spot; obtaining the second rotation matrix between the laser spot and the IMU coordinate system; and performing high-precision indication calibration of the laser spot image in laser measurement based on the calibration results of the second rotation matrix, translation vector, and the first rotation matrix, to perform high-precision measurement of local space.

6. A laser, inertial and image recognition joint calibration system, characterized in that: include: A checkerboard leveling module for testing is used to set a parameter calibration checkerboard on a marble platform for testing, and level the parameter calibration checkerboard; The inertial navigation IMU internal parameter calibration module performs IMU static parameter calibration and IMU dynamic parameter calibration on the inertial navigation IMU and corrects the IMU error; The laser irradiation visual shooting module irradiates the laser spot of the laser on the parameter calibration checkerboard, and uses the machine vision camera to shoot the parameter calibration checkerboard from different angles to obtain a set of parameter calibration checkerboard photos; The parameter joint calibration and correction measurement module performs joint calibration of machine vision cameras, inertial navigation IMUs, and laser parameters, enabling automatic correction of external parameters of various precision positioning measurement instruments and high-precision measurement of local spaces.

7. The laser, inertial and image recognition joint calibration system according to claim 6, characterized in that: Checkerboard leveling module for detection, including: A detection platform chessboard setting unit is used to set parameter calibration chessboard grids on the marble platform used for detection; The chessboard leveling unit uses a marble platform for testing and a high-precision level to level the parameter calibration chessboard and obtain the horizontal static parameter calibration chessboard; Setting a parameter calibration checkerboard on a marble platform for testing includes: spraying a first layer of checkerboard on the surface of the marble platform for testing through hollow shielding; spraying a second layer of checkerboard after the first layer of checkerboard is dry, and polishing the surface with high precision after the spraying is dry to form a parameter calibration checkerboard after high precision polishing.

8. The laser, inertial and image recognition joint calibration system according to claim 6, characterized in that: Inertial navigation IMU internal parameter calibration module, including: IMU static error calibration unit, which calibrates the static parameters of the inertial navigation IMU through the six-plane method and corrects the static error of the inertial navigation IMU; The dynamic error calibration and correction unit calibrates the gyroscope through the turntable, calibrates the dynamic parameters of the inertial navigation IMU, and corrects the dynamic error of the inertial navigation IMU; The static parameter calibration of the inertial navigation IMU through the six-plane calibration method includes: placing the three axes of the inertial navigation IMU facing downward and upward for a set time, obtaining the six-plane measurement data of the three axes of the inertial navigation IMU; calibrating the static parameters of the inertial navigation IMU according to the error between the static acceleration and the gravity acceleration, and correcting the static error of the inertial navigation IMU.

9. The laser, inertial and image recognition joint calibration system according to claim 6, characterized in that: Laser irradiation visual shooting module, including: A laser irradiation unit irradiates a laser spot on the parameter calibration checkerboard; The machine vision camera unit uses the machine vision camera to photograph the parameter calibration checkerboard from different angles; during the photographing process, the machine vision camera is stationary and photographs no less than two pictures of the parameter calibration checkerboard to obtain a set of picture of the parameter calibration checkerboard; The laser parameter inertial navigation output unit records the pixel coordinate system of the laser spot in the image at the static moment, the laser ranging distance, and the inertial navigation IMU accelerometer output at the static moment during static shooting.

10. The laser, inertial and image recognition joint calibration system according to claim 6, characterized in that: Parameter joint calibration and correction measurement module, including: The parameter association joint calibration unit establishes parameter associations between the machine vision camera, inertial navigation IMU, and laser, and performs parameter joint calibration based on the parameter associations, thus realizing automatic correction of external parameters of various precision positioning measurement instruments. Automatic calibration measurement unit, which automatically calibrates based on external parameters of various precision positioning measurement instruments to perform high-precision measurements in local space; Establish parameter associations among machine vision cameras, inertial navigation IMUs, and lasers, and perform joint parameter calibration based on the parameter associations, including: obtaining the camera optical center position and camera posture in the parameter calibration checkerboard coordinate system at all shooting moments, and obtaining installation deviations; using homography transformation to obtain the physical coordinates of the laser spot in the parameter calibration checkerboard coordinate system; obtaining the first rotation matrix and translation vector between the camera and the laser spot; obtaining the second rotation matrix between the laser spot and the IMU coordinate system; and performing high-precision indication calibration of the laser spot image in laser measurement based on the calibration results of the second rotation matrix, translation vector, and the first rotation matrix, to perform high-precision measurement of local space.

Images